# bivouac/helpers/view/scriptaculous
require 'active_support'

module BivouacHelpers
  module ScriptAculoUsView
    unless const_defined? :TOGGLE_EFFECTS
      TOGGLE_EFFECTS = [:toggle_appear, :toggle_slide, :toggle_blind]
    end

    # Returns a JavaScript snippet to be used on the Ajax callbacks for starting visual effects.
    def visual_effect(name, element_id = false, js_options = {})
      element = element_id ? element_id : "element"

      js_options[:queue] = if js_options[:queue].is_a?(Hash)
        '{' + js_options[:queue].map {|k, v| k == :limit ? "#{k}:#{v}" : "#{k}:'#{v}'" }.join(',') + '}'
      elsif js_options[:queue]
        "'#{js_options[:queue]}'"
      end if js_options[:queue]

      if TOGGLE_EFFECTS.include? name.to_sym
        %(Effect.toggle(#{element.inspect},'#{name.to_s.gsub(/^toggle_/,'')}',#{options_for_javascript(js_options)}))
      else
        %(new Effect.#{name.to_s.camelize}('#{element}',#{options_for_javascript(js_options)}))
      end
    end
    
    # Makes the element with the DOM ID specified by +element_id+ sortable
    # by drag-and-drop and make an Ajax call whenever the sort order has
    # changed. By default, the action called gets the serialized sortable
    # element as parameters.
    #
    # See http://script.aculo.us for avalaible options.
    # 
    # If you wan't to use +onChange+ and/or +onUpdate+ you can pass a javascript string
    # or a Hash, if you want to call a remote function.
    #
    # Example:
    #   ul( :id => 'my_list' ) do
    #     li "Google"
    #     li "Yahoo"
    #     li "Accoona"
    #     li "Ask.com"
    #     li "Baidu"
    #     li "Exalead"
    #     li "Voila"
    #     li "Lycos"
    #   end
    #   sortable_element( 'my_list', 
    #     :onChange => { 
    #       :url => R(SaveListOrder), 
    #       :success => visual_effect( :highlight, 'my_list' ) 
    #     } 
    #   )  
    def sortable_element( element_id, options = {} )
      javascript_tag( sortable_element_js( element_id, options ) + ";\n" )
    end
    
    def sortable_element_js( element_id, options = {} ) #:nodoc:
      if options[:onUpdate].is_a?( Hash )
        options[:onUpdate][:with] ||= "Sortable.serialize('#{element_id}')"
        options[:onUpdate] = "function(){" + remote_function(options[:onUpdate]) + "}"
      elsif options[:onUpdate].is_a?( String )
        options[:onUpdate] = "function(){" + options[:onUpdate] + ";}"
      end
      
      if options[:onChange].is_a?( Hash )
        options[:onChange][:with] ||= "Sortable.serialize('#{element_id}')"
        options[:onChange] = "function(){" + remote_function(options[:onChange]) + "}"
      elsif options[:onChange].is_a?( String )
        options[:onChange] = "function(){" + options[:onChange] + ";}"
      end

      [:tag, :overlap, :constraint, :handle].each do |option|
        options[option] = "'#{options[option]}'" if options[option]
      end

      options[:containment] = array_or_string_for_javascript(options[:containment]) if options[:containment]
      options[:only] = array_or_string_for_javascript(options[:only]) if options[:only]
      
      %(Sortable.create(#{element_id.inspect}, #{options_for_javascript(options)}))
    end
    
    def unsortable_element_js( element_id ) #:nodoc:
      %(Sortable.destroy(#{element_id.inspect}))
    end
    
    # Makes the element with the DOM ID specified by +element_id+ draggable.
    #
    # Example:
    #   draggable_element("my_image", :revert => true)
    # 
    # You can change the behaviour with various options, see
    # http://script.aculo.us for more documentation.
    def draggable_element(element_id, options = {})
      javascript_tag(draggable_element_js(element_id, options) + ";\n")
    end
    
    def draggable_element_js(element_id, options = {}) #:nodoc:
      %(new Draggable(#{element_id.inspect}, #{options_for_javascript(options)}))
    end

    # Makes the element with the DOM ID specified by +element_id+ receive
    # dropped draggable elements (created by draggable_element).
    # and make an AJAX call. By default, the action called gets the DOM ID 
    # of the element as parameter.
    #
    # Example:
    #   drop_receiving_element("my_cart", :onDrop => {
    #     :url => R(CartAdd),
    #     :update => 'drop-info'
    #   } )
    #
    # You can change the behaviour with various options, see
    # http://script.aculo.us for more documentation.
    def drop_receiving_element(element_id, options = {})
      javascript_tag(drop_receiving_element_js(element_id, options) + ";\n")
    end
    
    def drop_receiving_element_js(element_id, options = {}) #:nodoc:
      if options[:onDrop].is_a?( Hash)
        options[:onDrop][:with] = "'id=' + encodeURIComponent(element.id)"
        options[:onDrop] = "function(element){" + remote_function(options[:onDrop]) + "}"
      elsif options[:onDrop].is_a?( String )
        options[:onDrop] = "function(){" + options[:onDrop] + ";}"
      end

      options[:accept] = array_or_string_for_javascript(options[:accept]) if options[:accept]    
      options[:hoverclass] = "'#{options[:hoverclass]}'" if options[:hoverclass]
      
      %(Droppables.add(#{element_id.inspect}, #{options_for_javascript(options)}))
    end
  end
end